DESCRIPTION: Background: Traumatic brain injury has been referred to as the signature injury of the Operation Iraqi Freedom/Operation Enduring Freedom/Operation New Dawn (OIF/OEF/OND) wars. Over 25,000 soldiers were diagnosed with mild traumatic brain injury (mTBI) in 2012 alone. Not only do soldiers have blast-related mTBI, estimates of comorbid Post Traumatic Stress Disorder (PTSD), range from 11% to 50%. Since neural mechanisms affected by mTBI and PTSD often are overlapping, it is suggested that mTBI and PTSD may have an additive effect on symptoms. Indeed, an estimated 44-50% of soldiers with mTBI/PTSD remain symptomatic after one-year, compared to an estimated 10% in sports related concussion. Both mTBI and PTSD are associated with deficits in executive functioning. Additional factors that accompany mTBI in combat Veterans are depression and sleep deficits. Consequently, the combination of all these factors, impact executive functions and result in combat Veterans who are struggling to live productive lives. An effective treatment of executive function is needed for Veterans diagnosed with mTBI. Goal Management Training (GMT) is a metacognitive intervention that has been validated in TBI. However, limitations in GMT studies raise questions regarding effectiveness of GMT in mTBI. Based on preliminary data, GMT improved significantly on a problem solving measure in Veterans with blast-related mTBI, but lacked transfer to everyday activities. Therefore, we developed a Smartphone application to enhance the transfer of GMT skills to everyday tasks. The purpose: of this randomized study is to determine the effect of an innovative treatment for executive functions, enhanced with Smartphone technology, in Veterans with multiple blast related mTBI. In addition to determining the overall benefit of GMT, the study will investigate the influence of comorbid factors, such as post-traumatic stress disorder, depression, sleep disorders and cognitive capacity. Method: Veterans diagnosed with repeat blast-related mTBI and executive function deficit will be recruited from two sites (Tampa and North Florida/South Georgia) by Speech Services. Veterans will be randomized to GMT (38 participants) or to a control treatment called Brain Health Workshop (BHW) (16 participants).The Tower of London, a measure of planning and problem solving will be used to determine response to treatment. Primary analysis will use two sample t-test to compare group A (intervention) and group B (control) on improvements in time to completion on the TOL. In addition, as an exploratory analysis, we will perform a regression analysis that includes treatment group, PTSD severity and their interaction as independent variables, to adjust for PTSD severity measured by Clinician Administered PTSD Scale and to investigate whether there is interaction between treatment group and PTSD severity. Additional, exploratory tertiary analysis using paired t-tests will determine whether treatment effect generalizes to executive function performance in everyday activities (BRIEF-A) or engagement in community participation (CRIS). To test the second specific aim, a general linear regression will be used to determine whether factors such as PTSD, sleep, depression or cognitive capacity is associated with response to treatment. Results: If the results support the hypothesis that GMT will improve executive functions than this cognitive intervention can be adapted to a tele-health method of delivery and tested in a larger clinical trial. Moreover, the influence of the four factors on response to treatment, can guide future studies to determine which patients are likely to benefit from GMT.